In prior art, it is known to use lever type connectors when male and female elements having 20 or more contacts are to be connected and where a large coupling force is required. By doing so, male and female connectors can easily be coupled with a relatively small force as a result of the leverage obtained.
The conventional lever type connectors include a (1) a male connector housing formed with a hood so that a female connector housing can be inserted, (2) a notch which extends in the direction of insertion and withdrawal of the female connector housing, so as to permit the insertion of a guide pin projecting outward from a side surface of the female connector housing, and (3) a lever which is rotatably supported and has a slanting surface opposite the notch. The slanting surface is formed so that it is not on the notch when the lever is in its initial position, but moves toward the back of the notch as the lever is rotated.
In this construction, as the female connector housing is inserted into the hood of the male connector housing, the guide pin is guided to the vicinity of the entrance of the notch. However, terminal fittings carried by the male and female connectors come into contact, thereby hindering the insertion of the guide pin into the notch. When the end of the lever is held and rotated in this state, the slanting surface of the lever moves toward the back of the notch and the guide pin is pressed into the back of the notch thereby. The male and female connectors can easily be coupled with a small force because the distance the guide pin is pressed into the notch is short and the rotating range of the lever is large.
With the conventional connectors as mentioned above, the lever is rotated after the female connector housing is inserted until the slanting surface engages with the guide pin; the female connector housing is then pressed into the male connector housing. However, despite the fact that the lever is rotated fully, the female connector housing may not yet be completely inserted to the specified position. Thus, the male and female connectors are accurately coupled, resulting in a bad or insufficient electrical connection or even no electrical connection at all. In a worse case, it may not be noticed that these connectors are only partially coupled.
There are applications, e.g., in motor vehicles or medical apparatus, where perfect electrical connections are absolutely indispensable, e.g., for security reasons. For these applications, the known connectors are not suitable since, if the mating connectors are inserted into each other, there is no certainty that a proper electrical connection has been achieved. In view of the above problem, it is an object of the Invention to provide a connector which can be coupled with a small force and is free from coupling failure such as partial coupling.